A recently published article has great information about weight and breathing. Simple conclusion: is that being overweight with Myotonic Dystrophy can affect your breathing and respiratory function. Since respiratory failure and pneumonia are big issue with Myotonic Dystrophy pay special attention to your weight!!! It also showed that a great majority of people with DM have an abnormal body composition. ITs important to keep the weight off but you also must see a nutritionist to insure that you are getting proper nutrition and to look at your body weight/mass/BMI. Here is the summary

InDM1 patients, overweight is an independent factor for predicting TLC, and contributes independently of FIV1. Because overweight isr elated to increased work of breathing and inspiratory muscle strength is reduced inDM1, the fatigue threshold will be reached sooner. Therefore, muscle fatigue and the onset of respiratory failure will develop at an earlier stage in overweight patients, especially during increased ventilator demand. Moreover, over half of DM1patients are overweight, and nearly all patients have an abnormal body composition. To develop interventional strategies for weight loss, it will be important to categorize the individual type of body composition. Hence, preventing the development of overweight inDM1 patients may result in delaying respiratory failure and mortality in DM1.

Abstract

Reported herein are two cases of severe phenotype of congenital myotonic dystrophy (CDM) with presentation of respiratory insufficiency at birth. The infants were successfully managed with bi-level positive airway pressure (BiPAP) via nasal mask. The use of BiPAP in infants with CDM has not been reported before. The rationale for using BiPAP is discussed. BiPAP may be more effective than continuous positive airway pressure in managing respiratory insufficiency, especially in infants with the more severe phenotype of CDM.

My son Chris has had multiple issues with Pneumonia including multiple hospitalizations and ventilator support. I found this nice article on Respiratory support that is pretty technical. The part on General measures is below and you can link here to the actual article..Respiratory Consequences or Neuromuscular Disease. We have done the following with Chris

Background: In many studies of patients with muscle weakness, chronic hypercapnia has appeared to be out of proportion to the severity of muscle disease, indicating that factors other than muscle weakness are involved in CO2 retention. In patients with COPD, the unbalanced inspiratory muscle loading-to-strength ratio is thought to trigger the signal for the integrated response that leads to rapid and shallow breathing and eventually to chronic hypercapnia. This mechanism, although postulated, has not yet been assessed in patients with muscular dystrophy.

Subjects
Twenty consecutive patients (10 men) with a mean age of 47.6 years (range, 23 to 67 years) were studied: 11 patients with limb-girdle dystrophy (LGD), 3 with Duchenne muscular dystrophy, 2 with amyotrophic lateral sclerosis, 1 with Charcot-Marie-Tooth syndrome, 1 with Becker muscular dystrophy, 1 with MD, 1 with facioscapulohumeral dystrophy, and no respiratory complaints. Nine were ambulatory, and 11 were wheelchair bound. The standard criteria were used to select patients. 20,21

None of the patients had a scoliosis nor any abnormalities on chest radiograph nor obvious abnormalities in diaphragm placement. Five patients were current mild smokers (<=5 pack-years).

Seventeen normal subjects matched for age (range, 26 to 62 years; mean, 41.5 years) and sex (8 men) were studied as a control group. The study was approved by the local ethics committee, and the subjects gave their informed consent.

The anthropometric characteristics of the patients are shown in Table 1.

Functional Evaluation

Routine spirometry, obtained with the patients seated in a comfortable armchair, was measured as previously described. 13,16,22 Functional residual capacity (FRC) was measured by the helium dilution technique. The normal values for lung volumes were those of the European Community for Coal and Steel. 23 Arterial blood gas tensions were measured with a blood gas analyzer (IL-1304; Instrumentation Laboratory; Milan, Italy).

Protocol All subjects were tested in the morning. Before the experiment, the subjects were well acquainted with the laboratory and equipment. An arterial blood sample and lung function tests were performed, and then changes in volume, flow, and Ppl were recorded. Finally, the respiratory muscle strength tests were performed in each patient.

Data Analysis
Volume and time components of the respiratory cycle, RL, and Eldyn were averaged in each patient over 30 consecutive breaths. Eldyn was expressed both as an actual value and as a percent of Pplsn, an index of the balance between the elastic load of the lung relative to the maximal inspiratory force available. Single and stepwise multiple regression analyses were performed to assess relationships between variables. The statistical analysis we carried out considers the dependency of a variable (eg, the level of PaCO2) on a series of independent variables. The effect of each variable on PaCO2 was evaluated independent of the effect of all other variables. In a multivariate analysis, a rule of thumb is to limit the number of variables as a function of the number of patients.28 Thus, multiple regression analysis with stepwise selection of the independent variables was carried out relating PaCO2 to functional variables. The proportion of total variance in the dependent variable accounted for by the predicted variables is reported as the square of the correlation coefficient (r2). Single regression analysis was performed using Pearson’s single correlation coefficient. Comparisons between groups were made using the Mann-Whitney U test. A value of p < 0.05 was considered as the threshold of statistical significance. Data are presented as mean ± SD unless otherwise specified. .

Results

Clinical, anthropometric, and respiratory function characteristics of the patients (and control subjects) are shown in Table 1. As shown in Table 1, vital capacity (VC) was reduced in 11 patients, as was total lung capacity in 9. The means of MIP (47.8 ± 28.3 cm H2O; range, 11 to 127 cm H2O; p = 0.00001) and MEP (49.5 ± 26.2 cm H2O; range, 15 to 104 cm H2O; p = 0.00002) were significantly lower than in control subjects. In 11 patients and 10 patients, the values of MIP and MEP, respectively, were lower than the mean – 2 SD of the value calculated for the control subjects. Arterial blood gases were normal in all but eight patients in whom PaCO2 was considered to be high (>= 45 mm Hg) and in three patients in whom PaCO2 was low (< 80 mm Hg). In some of the patients, and particularly in patients 12 and 14, in whom PaCO2 was normal, a high level of ventilation was found.

Discussion

We have found that in patients with NMD, Eldyn (%Pplsn) is the strongest predictor of the variance in PaCO2. Increased Eldyn (%Pplsn) was associated with a decreased TI, which truncates VT, thereby leading to chronic CO2 retention (PaCO2).